409/425 Fuel Mileage

[JimKwiatkowski]

Does anyone have any good timing setting for a 409/425 ? I'm going on a 500 mile road trip with the 57 next week and I would like to know does anyone get better than 11 MPG ? Last year I ran my timing between 34 to 36 deg @ 2000 rpm,18 deg @ idle,3.55 rear gears and driving 60 mph,I got 11 mpg .

 

[quik9r]

mileage

I would say that is pretty good. In 1997 myself and two uncles drove to Youngstown Ohio, the lead car a 61 348/350hp tripower 4 speed 3:70 gears, all the way with fuel to spare (6 hour drive). My car 409/380 hp single carb 4 speed and 3:70 gears,needed fuel ( 4.5 Hours), I figured I got 13 mpg. The last car a 409/425hp 4 speed 3:70 gears needed two fuel stops to get there. Mileage was around 8 mpg. I think you are doing very well at 11 mpg. The next thing would be a gearvendors overdrive unit!

Kevin

 

[PAINTJOHN1]

Jim,I'd say your doing pretty good with 11 miles per gallon.My 1964 Impala 409/425 usually gets about 8-9 miles per gallon. John

 

[Fathead Racing]

Jim, check the timing at 2500/2800 rpm, sitting in the driveway, leaning over the fender. Vacuum advance hooked up to timed vacuum port. With initial, mechanical and vacuum advance in full at 2500/2800 rpm, a good number for your car is between 48 and 50 dgs advance. I know that with your distbutor you can limit vacuum advance. This will give you the best cruise economy. The vacuum advance unit is the best thing for fuel mileage and keeping the plugs clean at cruise rpm. Or pull into my garage at 477 Center rd. and I will fix you up!

 

[Tom Kochtanek]

Freeway only

Jim:

As you probably know I've been on at least three extended trips with my '62 car, with the stroker engine and dual quads. Rear end is 3.36 posi.

On the initial trip I was mostly on the freeway and was averaging 12.8 MPG. I had hundreds of pounds of books, clothes and such for a one month visit. Last year's trip to Norwalk I brought my buddy James and a bunch of spare parts and I think we ran around 12 MPG. That's with stock 14" wheels and tires.

I try not to check it around town, might get bummed out. I rarely hit the second carb when cruising, but around town I somehow get into it on the back roads. Did that today for a bit... Made me feel better about not being in Bowling Green this past weekend .

Cheers!
TomK

 

[JimKwiatkowski]

Jim, check the timing at 2500/2800 rpm, sitting in the driveway, leaning over the fender. Vacuum advance hooked up to timed vacuum port. With initial, mechanical and vacuum advance in full at 2500/2800 rpm, a good number for your car is between 48 and 50 dgs advance. I know that with your distbutor you can limit vacuum advance. This will give you the best cruise economy. The vacuum advance unit is the best thing for fuel mileage and keeping the plugs clean at cruise rpm. Or pull into my garage at 477 Center rd. and I will fix you up!

Ray,after my MSD Ignition broke down going to Norwalk last year,I switched back to my Mallory Ignition with a Unlite Distributor that has a mechanical advance.The reason I switched back to Mallory,is I was told that the only way to know what failed in my MSD distributor or,my 6AL box was to send them back to MSD to be tested and repaired.I now have 2 Mallory Unlite Distributors,I carry 1 as a spare so if my ignation breaks down on a long trip I can change my disributors like a spare tire.

 

[JimKwiatkowski]

Jim:

As you probably know I've been on at least three extended trips with my '62 car, with the stroker engine and dual quads. Rear end is 3.36 posi.

On the initial trip I was mostly on the freeway and was averaging 12.8 MPG. I had hundreds of pounds of books, clothes and such for a one month visit. Last year's trip to Norwalk I brought my buddy James and a bunch of spare parts and I think we ran around 12 MPG. That's with stock 14" wheels and tires.

I try not to check it around town, might get bummed out. I rarely hit the second carb when cruising, but around town I somehow get into it on the back roads. Did that today for a bit... Made me feel better about not being in Bowling Green this past weekend .

Cheers!
TomK

Tom,thats good MPG what timing are you running ?

 

[roger gunter]

Jim
I have the 409/425 in my 61
running 356 gears with p235-60r 15 tires
crusing on the highway at 65 mph I am taching 3000
all i can get is about 10 mpg
timing is set at 14 deg. ( I think )

good luck

Roger

 

[rstreet]

Jim:

As you probably know I've been on at least three extended trips with my '62 car, with the stroker engine and dual quads. Rear end is 3.36 posi.

On the initial trip I was mostly on the freeway and was averaging 12.8 MPG. I had hundreds of pounds of books, clothes and such for a one month visit. Last year's trip to Norwalk I brought my buddy James and a bunch of spare parts and I think we ran around 12 MPG. That's with stock 14" wheels and tires.

I try not to check it around town, might get bummed out. I rarely hit the second carb when cruising, but around town I somehow get into it on the back roads. Did that today for a bit... Made me feel better about not being in Bowling Green this past weekend .

Cheers!
TomK

Tom: I didn't realize you had an economy run coming to Norwalk last year considering all of the bugs you killed on the way. I was thinking 70-80 MPH by the looks of those bugs I saw. Phil didn't have as many on the Harley's I noticed. Of course I didn't have too many bugs due to the limited towing horsepower I had
robert

 

[jester]

Mpg

My last trip to the Syracuse Nationals was agout 150 miles. My 409/425 with 373's and 27 inch tires got 15 mpg. That was cruising about 60 mph. I use 28 degrees total advance , all in by 2500 rpm's. Mechanical advance only . It also required some restrain on my part ( keeping my foot out of it ) Temp never went over 195 in 90 degree weather.

 

[JimKwiatkowski]

My last trip to the Syracuse Nationals was agout 150 miles. My 409/425 with 373's and 27 inch tires got 15 mpg. That was cruising about 60 mph. I use 28 degrees total advance , all in by 2500 rpm's. Mechanical advance only . It also required some restrain on my part ( keeping my foot out of it ) Temp never went over 195 in 90 degree weather.

Good job jester,thats Great mileage

 

[rstreet]

Impressive mileage Jester even without vacuum advance
robert

 

[409dog]

Fuel mileage

Here is a little item I used back in 1961 on my Impala Convertible, 348, 350 hp, 3 duce, 4 speed. It is a Stewart Warner Motor Minder. But any vacuum gauge will do. The idea is to cruise at the highest vacuum reading without losing speed.
And if you are a poor driver, one of those on the gas off the gas types, this is a good visual reminder of what your foot is doing.

On the gas under load going up hill the vacuum will fall into the orange or red.
Wide open red. Coasting off the gas or down hill the needle moves to yellow.

It is just a little helper to keep you focused while your motoring down the road.
Try it you'll like it! John

 

[rstreet]

Had a 63 Gran Prix with one of those stock in the console where the tach WOULD have gone if it was a 4 speed. Learned a lesson and the 65 2 +2 was a 4 speed.

 

[yellow wagon]

Had a 63 Gran Prix with one of those stock in the console where the tach WOULD have gone if it was a 4 speed. Learned a lesson and the 65 2 +2 was a 4 speed.

I think a lot of the auto Pontiacs had them. A buddy of mine had one in his 64 LeMans also in the console

 

[dq409]

My `65 Impala SS had one in the console also !!
Back then who cared,, gas was 28 cents a gallon !!


Speaking of gas,,

Gas was $1.47 when Bush was sworn in (the first time)!!

 

[Ronnie Russell]

Yeah, you are right Jim. Gasoline prices are all Bush's fault, along with hurricanes, floods, fires, and all of the World's problems. If only he would allow for new domestic drilling and new refineries. Won't be long til Novermber and everything will be great again. $1.50 gas and peace in the World.

 

[skipxt4]

 

[dq409]

Yeah, you are right Jim. Gasoline prices are all Bush's fault, along with hurricanes, floods, fires, and all of the World's problems. If only he would allow for new domestic drilling and new refineries. Won't be long til Novermber and everything will be great again. $1.50 gas and peace in the World.

Now,,,, did I really say it was his fault??

Or was I just giving a fact !!??







Not going to get into a political head banging,,,:stooges

 

[rstreet]

oh oh don't get DQ wound up tight again as it's not a pleasant sight
robert